# My Sadistic Boyfriend
## Part I: Introduction to the Characters and Setting
- Chiaki
- Protagonist of the story
- Roommate and girlfriend of Katsuho
- Best friend is Mamiya
- Katsuho
- The unofficial school prince
- Dazzling and popular in public
- Secretly a sadist with a perverted streak when alone with Chiaki
- Mamiya
- Chiaki's best friend
- Close to Mitsuru
- Considering leaving to study abroad
- Mitsuru
- Second most popular boy in school
- Handsome and admired by many
- Planning to leave for studying abroad
## Part II: The School's Reaction to Mitsuru's Departure
- School's Uproar
- News of Mitsuru leaving spreads quickly
- Students are shocked and saddened
- Speculation about Mamiya leaving with him
- Chiaki's Emotional Turmoil
- Struggles with the potential loss of her best friend
- Feels torn between her loyalty to Mamiya and her relationship with Katsuho
- Begins to notice changes in Katsuho's behavior
## Part III: Katsuho's Unusual Behavior
- Changes in Katsuho
- Becomes more distant and secretive
- Acts jealous and possessive towards Chiaki
- Displays increased sadistic tendencies
- Chiaki's Observations
- Notices Katsuho's mood swings
- Tries to understand the reasons behind his behavior
- Feels conflicted about confronting him
## Part IV: Conflict and Resolution
- Chiaki's Internal Conflict
- Balances her feelings for Katsuho and her friendship with Mamiya
- Questions the future of her relationship with Katsuho
- Decides to confront Katsuho about his behavior
- Katsuho's Confession
- Reveals his insecurities about losing Chiaki
- Admits to feeling threatened by Mitsuru and Mamiya's closeness
- Promises to work on his behavior and be more open with Chiaki
- Conclusion
- Chiaki and Katsuho reconcile and strengthen their bond
- Mamiya decides whether to stay or leave with Mitsuru
- The story ends with a sense of growth and understanding among the characters